What is scrub typhus | Explained

A 2021 systematic review noted that scrub typhus, a common acute febrile illness, is a “grossly under-recognized public health problem in India. (Representative image) | Photo Credit: Getty Images/iStockphoto

The death of Anna University student at Government Kilpauk Medical College Hospital (KMCH) due to scrub typhus on Friday (September 18, 2026) has again brought this bacterial infection to the fore. University authorities said they have also started screening students for typhoid, dengue and leptospirosis.

What is scrub typhus?

Scrub typhus is a bacterial infection caused by the bacterium Orientia tsutsugamushi. It is spread by the bite of infected larval mites or ticks – it is not a mosquito-borne disease.

Bush typhus is a major public health burden in South and Southeast Asia. AND 2021 systematic review noted that scrub typhus, a common acute febrile illness, is “a grossly under-recognized public health problem in India”. He reported that the proportion of scrub typhus in acute undifferentiated febrile illness (AUFI) studies was 25.3% and the community seroprevalence was 34.2%. The review also noted that the disease causes significant morbidity and is responsible for a large number of deaths, with its bueden being “underappreciated”.

AND 2025 multicenter study 587 children with acute encephalitis syndrome (AES) from Karnataka, Andhra Pradesh and Tamil Nadu revealed that scrub typhus is now the most common infectious cause of AES in South India.

What are the symptoms?

Symptoms usually begin within 10 days of infection. The United States Center for Disease Control and Prevention (CDC) lists the symptoms of typhoid fever as: fever and chills, headache, body and muscle aches, a dark, scaly area at the site of the chigger bite (also known as an eschar), mental changes ranging from confusion to coma, enlarged lymph nodes, and a rash.

Early treatment is critical. If left untreated, severe illness from typhoid infection can lead to acute respiratory distress syndrome (ARDS), shock, meningitis and kidney failure, which can be fatal, the research paper says. Incidence of scrub typhus in rural South India published in The New England Journal of Medicine last year.

Typhoid mortality is high in India, mainly due to late diagnosis and treatment.

How is it diagnosed and treated?

Since the symptoms of scrub typhus are common to those of several other diseases, the diagnosis is often delayed. A blood test (IgM ELISA or PCR) can help confirm the diagnosis.

Ringworm should be treated with the antibiotics doxycycline or azithromycin. If the treatment is started in time, it is effective. Results of a study conducted at seven centers in India, published in 2023in which patients were randomly assigned to receive a combination of doxycycline and azithromycin, showed faster resolution of complications compared to two other arms where patients were given monotherapy with either doxycycline or azithromycin. The frequency of respiratory, renal, hepatic, and central nervous system complications was lower in the combination therapy group than in either monotherapy group.

How can this be prevented?

There is no vaccine against typhus yet. The infection is not contagious.

Chiggers live in areas with lots of grass, dense vegetation, agricultural fields, plant litter and bare soil in rural areas of Asia and usually feed on small mammals such as rats and shrews.

Protection from being bitten by protective clothing, covered shoes and the use of insect repellants can help. Ensuring a clean and well-maintained environment can also help reduce dust mites.

“Early diagnosis and prompt treatment can significantly reduce complications and mortality. Good surveillance and appropriate control measures are urgently needed,” the 2021 report said.

Published – 22 Sep 2026 08:37 IST